Terminal



July 15, 1941. G. H. HAMM ETAL TERMINAL- Filed Nov. 9, 1939 Inventors: Claude A. Ja Geo1" V71 em 9 eH.H 39

Th if Attorn ey.

Patented July 15, 1941 TERMINAL George H. Hamm and Claude A. Jagger, Schenectady, N. Y.,

assignors to General Electric Company, a corporation of New York Application November 9, 1939, Serial No. 303,641

2 Claims.

Our invention'relates to terminals, more particularly to detachable and adjustable terminals for resistors and has for its object a simple, reliable and low cost terminal.

For a more complete understanding of our invention, reference should be had to the accompanying drawing in which Fig. 1 is a front elevation view of an electric resistor provided with a terminal embodying our invention; Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1, while Fig. 3 is a view in perspective of the terminal showing the two parts separated.

Referring to the drawing, we have shown our invention in one form as applied to a round resistance'wire I wound in helical form on a heat refractory electrically insulating support II. The

support is made of a suitable material such as porcelain. It has a central substantially square portion lid with each corner projecting outward to form supports I! to IE inclusive on which the wire is wound. Each of these supports is provided with a series of spaced recesses or depressions l6 in which the wire is laid and by means of which the turns are held in position.

It will be observed that each turn of the resistance wire has portions extending between the supports l2 to I5 inclusive which portions are in spaced relation with the support. Our terminal is adapted for application to thesespaced wire portions and, as shown, the terminal I6 is applied to the portion of a resistor turn, ll.

As shown in Fig. 3, the terminal consists of two complementary members or parts Ito and I 6b made of a suitably rigid electrically'conducting material such as steel. The part l6b has a projecting end i8 forming a quick detachable electrical connection by means of which the terminal can be connected to an electric circuit, this projection being provided with a clamping bolt l8a which extends through an aperture in it. Also the part I6?) is provided with a fiat bottom transverse gioove or recess I 9 to receive the resistor wire and its lower end is forked, providing two projections having their lower ends bent outward laterally away from the part |6a to form two supporting feet and 2| which engage the plane surface of the insulating support ll between the supports l2 and I3.

' The part I611 of the terminal also has a fiat bottom groove or recess 22 to receive the resistor wire and its forked lower end has two projections bent outwardly away from the part lib to form two feet 23 and 24 which also engage the support II. The part I611 is provided with an aperture 25 through which extends a clamping screw or bolt 26 cooperating with a tapped hole 21 in the part l6b. Also the part l6a has two spaced lateral projections 28 and 29 at the top which projections are bent toward the other part I61) and embrace a narrow upper portion 30 on the part l6b. The two parts are held thereby with the grooves I9 and 22 in parallel relation with each other and with the feet 20, 2|, 23 and 24 in a predetermined plane at right angles with the grooves I9 and 22.

A central laterally extending portion 3| between the projections 28 and 29 is in abutting engagement with the portion 30 and holds the upper end of the part Hi spaced from the other part a distance somewhat greater than the diameter of the resistor wire i0 so that when the terminal I6 is applied to the Wire with the wire lying in the grooves l9 and 22 the two parts [6a and I6!) including the surfaces of the recesses l9 and' 22 in engagement with the wire, diverge somewhat away from each othr in a direction away from the support ll or in an upward direction as seen in the drawing; The purpose'of this is to assure that the feet 20, 2!, 23 and 24 are held firmly against the support H, the diverging flat surfaces of the recesses i9 and 22 tending to force the wire upward between the parts of the terminal and thereby slidably bias the terminal toward the support so that the feet are forced against the support.

In applying the terminal to the resistorit may be necessary to separate the two parts Mia and l6b by removing the screw 26 especially when the terminal is applied to an intermediate turn as shown in Fig. 2. Each part is tilted so that its feet pass between the adjacent resistor turn and the turn to which the terminal is to be applied and then the part is tilted to an upright position. When the two parts have been thus assembled to the resistor, the clamping screw 26 is put in place and the parts are drawn together so that their lower ends are clamped firmly against the resistor portion lying in the grooves l9 and 22. Preferably while the screw 26 is being tightened, the terminal parts are pressed downward so that the feet rest on the insulating support. When thus applied, the terminal is clamped firmly to the resistor portion in good electrically conducting relation therewith and furthermore by the engagement of the-feet with the support, it is firmly secured against turning movement about the resistor portion. It is contemplated that the resistor wire will have considerable rigidity so that it will not spring outward appreciably when substantial forces are applied to the terminal.

Moreover, it will be observed that the Widest central portion of the terminal containing the two grooves i9 and 22 for the wire is substantially as wide as the distance between the two supports i2 and [3. As shown in Fig. l, the central portion at its opposite sides extends adjacent the trio supports 12 and 53. This construction takes advantage to the fullest extent of the rigidity of the resistor wire for it will be observed that any force applied to the terminal is substantially taken up by the very short portions of the resistor turn at each side of the terminal between the terminal and the adjacent support.

While we have shown a particular embodiment of our invention, it will be understood, of course, that we do not wish to be limited thereto, since many modifications may be made and we, therefore, contemplate by the appended claims to cover any such modifications as fall within the true spirit and scope of our invention.

'What we claim as new and desire to secure by Letters Patent of the United States is:

1. A terminal for a substantially rigid round resistor wire wound on an insulating support and having a portion of a turn in spaced relation with said support, comprising two complementary members provided with registering grooves having fiat bottoms, means for clamping said members together with the resistor wire portion in said grooves clamped between the fiat bottoms of said grooves, a projection on the lower end of each of said members extending laterally outward in a direction away from the other member and engaging said support so as to secure said terminal against turning movement on the resistor wire, and means carried by said members for spacing the upper ends of said members apart a distance greater than the lower ends of said members so that the flat bottoms of said grooves when clamped on the resistor wire diverge with respect to each other in an upward direction thereby to bias slidably said members on the resistor wire toward said support and force said projections against said support.

2. A terminal for a substantially rigid resistor wire wound on an insulating support having supporting projections whereby a. portion oi a turn is in spaced relation with said support, compris- 15 ing two complementary members provided with registering flat bottom grooves, a screw for clamping said members together with said portion of the resistor wire between them clamped in said grooves, a pair of projections on the lower end of each of said members extending laterally outward in a. direction away from the other member and engaging said support so as to secure said terminal against turning movement on the portion of a turn, cooperating projections on the upper ends 01 said members for securing said members against turning movement with respect to each other about said screw, and spacing means carried by one of said members for spacing said members with the bottoms of said grooves diverging with respect to each other in a direction away from said support thereby to bias slidably said members on the resistor wire toward said support and force said projections against said support.

GEORGE H. HAMM.

CLAUDE A. JAGGER. 

